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Avaliação da madeira de Betula pendula, Eucalyptus globulus e de híbrido de Eucalyptus grandis x Eucalyptus urophylla destinadas à produção de polpa celulósica Kraft; Evaluation of the wood of Betula pendula, Eucalyptus globulus and of hybrid of Eucalyptus grandis x Eucalyptus urophylla as a raw-material for kraft pulp production

Duarte, Francismara Aparecida Sanches
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/06/2007 Português
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A madeira é a principal variável de custo na produção de polpa celulósica. A polpa celulósica obtida a partir da madeira de folhosas é principalmente utilizada para produção de papéis de escrita e impressão assim como, a produção de papéis para fins sanitários; para estes usos normalmente a polpa celulósica deve ser branqueada. Mundialmente, várias espécies de madeira de folhosas são utilizadas para produção de polpa celulósica de fibra curta, estando entre as principais o híbrido Eucalyptus grandis x Eucalyptus urophylla (Brasil), Betula pendula (Finlândia) Eucalyptus globulus (Portugal). Este projeto teve por objetivo: i-avaliar e comparar o desempenho de madeiras de principais espécies utilizadas mundialmente, para produção de polpa celulósica de fibra curta, considerando os aspectos relacionados à qualidade da madeira e polpa, o consumo de reagentes químicos na polpação e também os aspectos relacionados ao rendimento e a capacidade de produção de polpa celulósica; ii-fornecer informações estratégicas para o setor celulósico nacional com relação as possíveis ameaças e as oportunidades apresentadas pelos materiais não utilizados no Brasil, visando o conhecimento e posicionamento em competitividade destas madeiras no mercado mundial de celulose e papel; iii-fornecer subsídios para o programa genético e de melhoramento florestal; iv-posicionar a polpa celulósica de Eucalyptus grandis x Eucalyptus urophylla em relação as suas principais concorrentes. Para realização deste trabalho foram coletadas 5 árvores de todas as espécies...

Análise entre processos e matérias-primas para a produção de biodiesel; Analysis of processes and raw materials used for biodiesel production

Garcilasso, Vanessa Pecora
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 05/12/2014 Português
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A busca por alternativas ao uso de combustíveis fósseis vem se tornando cada vez mais necessária. Neste sentido, os biocombustíveis vêm se destacando por ser uma fonte de energia alternativa de grande viabilidade para o setor de transporte, maior consumidor de energia. O desafio é viabilizar a produção de biocombustíveis em larga escala, de maneira sustentável. Nesse contexto, o biodiesel apresenta-se como opção interessante para substituição/mistura ao diesel, com vantagens ambientais, pois emite menos gases como o CO, CO2 e SO2 na atmosfera. Nos últimos anos, políticas de incentivo à produção deram início à inserção do biodiesel na matriz energética nacional através do Programa Nacional de Produção e Uso do Biodiesel. Em 2005, a Lei nº. 11.097 determinou a introdução do biodiesel na matriz energética brasileira e, recentemente, fixou o valor em 7% para o percentual mínimo obrigatório de adição de biodiesel ao óleo diesel. Apesar do importante avanço proporcionado pela introdução legal do biodiesel no país, existem ainda muitas questões relacionadas à sua produção que precisam ser discutidas, tais como as diferentes condições de cultivo de matérias-primas e os diferentes processos para a obtenção do mesmo. Neste sentido o objetivo deste trabalho é analisar as matérias-primas e os processos de produção de biodiesel...

Avaliação dos parâmetros térmicos e calorimétricos das matérias-primas lipídicas e dos respectivos biodieseis produzidos; Evaluation of thermal and calorimetric parameters of lipid raw materials and their biodiesels produced

Oliveira, Levi Ezequiel de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 25/11/2014 Português
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O Brasil destaca-se em relação ao uso de fontes renováveis de energia com 41 % da matriz energética (biomassa e hidráulica) contra apenas 13% da média mundial. Desta forma, o país tem uma excelente oportunidade para desenvolver e aperfeiçoar novas matrizes energéticas associadas à produção de combustíveis através de fontes renováveis e que emitam baixa quantidade de dióxido de carbono um dos principais responsáveis pelo efeito estufa. No Brasil, a utilização do biodiesel se torna ainda mais relevante uma vez que a matriz do transporte brasileiro é predominantemente rodoviária (58%) na frente do ferroviário que vem em seguida com apenas 25%. Ainda vale destacar a enorme frota de caminhões no Brasil. Dentre os combustíveis mais consumidos destaca-se o diesel 39%, na frente da gasolina utilizada pelos automóveis com apenas 15% em relação ao consumo total de todos os combustíveis líquidos utilizados no Brasil. Portanto, torna-se estratégico para o país investir em programas de incentivo na produção, bem como em pesquisas para o desenvolvimento de processos de menor custo para a produção do biodiesel. O principal objetivo desse trabalho é avaliar parâmetros importantes de diferentes matérias-primas lipídicas e biodieseis...

Designing Activated Carbons from Natural and Synthetic Raw Materials for Pollutants Adsorption

Mourão, Paulo; Cansado, Isabel; Carrott, Peter; Carrott, Manuela
Fonte: Instituto Superior Técnico - Lisboa Publicador: Instituto Superior Técnico - Lisboa
Tipo: Artigo de Revista Científica
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Over the last decades the literature has shown the possibility of producing activated carbons (AC) from a wide variety of raw materials, and to use them as one of the most environment-friendly solutions for waste disposal [1]. Simultaneously, it has been shown that the adsorption of pollutants from different sources by activated carbons is one of the most efficient techniques for remediating or solving this kind of problem [2]. In this context, phenolic compounds represent one of the most important classes of pollutant present in the environment [3]. In this perspective, we present a study involving the production of AC from cork (Quercus suber L.), PEEK (polyetheretherketone) wastes or granulated recycled PET (polyethyleneterephthalate) and their applicability for the adsorption of phenolic compounds from the liquid phase. All samples were characterised in relation to their structural properties and chemical composition, by different techniques, including nitrogen adsorption at 77 K, elemental analysis (C, H, N, O and S) and point of zero charge (PZC). The activated carbons produced demonstrated high adsorption capacities both in the gas and liquid phase as exemplified by N2 and phenolic compounds adsorption experiments. Based on the structural and chemical properties...

Basalt mine-tailings as raw-materials for Portland clinker

Andrade,F. R. D; Pecchio,M; Bendoraitis,D. P; Montanheiro,T. J; Kihara,Y
Fonte: Associação Brasileira de Cerâmica Publicador: Associação Brasileira de Cerâmica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2010 Português
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Large volumes of waste materials are produced by crushing of basaltic rocks for aggregate production, which is widely used in regions that lack rocks of granitic or gneissic composition. Two types of waste materials are produced (a) quarry fines, which are in part used as fine aggregates in concrete and (b) vesicular basalt, a porous variety of basalt that is useless as aggregate. This paper presents a procedure to use basaltic mine-tailings as raw-mixtures for Portland cement by adjusting the proportion of the other raw-materials (limestone, clay, iron ore). It is demonstrated that there is no need for additional fluxes to the basalt-bearing raw-mixtures, since the setting of the chemical parameters is enough to guarantee clinker formation. Two series of experimental clinkers were synthesized with raw-mixtures containing residues from a basalt quarry that produces aggregates for concrete. Experimental clinkers were produced from raw-mixtures with similar lime saturation factors, silica and alumina modules, which were set by adjusting the proportions of limestone, clay and iron ore to the varying proportions of basaltic materials added to them. One series of clinkers was made with basalt quarry fines, which are in part used as fine aggregate...

Influence of local raw materials on the mechanical behaviour and fracture process of PVA-SHCC

Magalhães,Margareth da Silva; Toledo Filho,Romildo Dias; Fairbairn,Eduardo de Moraes Rego
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2014 Português
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This paper addresses the results of an investigation on the influence of the Brazilian raw materials on the mechanical performance of Strain Hardening Cementitious Composites (SHCC). The mixtures were produced with variations of fly ash/cement and sand/cement proportions and with different maximum sand particle. Mechanical properties were evaluated by direct tension, bending and compression tests. Crack formation under direct tension and bending loads was also investigated. The results indicate that the use of high quantities of fly ash with low quantities of fine sand is the ideal combination to obtain strain hardening composites with tensile strain capacity superior to 3% using local materials. The increase in the sand content and particle size affects the behavior of the composites and tended to reduce the strain capacity of the specimens by up to 30%. Keeping constant the fly ash/cement and sand/cement rates it was found that the crack density and width measured under direct tension are only affected by the diameter of the sand for tensile strains in the range of 2%. The same general trends were observed for specimens submitted to compressive and bending loads.

Leveraging “Raw Materials” as Building Blocks and Bioactive Signals in Regenerative Medicine

Renth, Amanda N.; Detamore, Michael S.
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica
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Components found within the extracellular matrix (ECM) have emerged as an essential subset of biomaterials for tissue engineering scaffolds. Collagen, glycosaminoglycans, bioceramics, and ECM-based matrices are the main categories of “raw materials” used in a wide variety of tissue engineering strategies. The advantages of raw materials include their inherent ability to create a microenvironment that contains physical, chemical, and mechanical cues similar to native tissue, which prove unmatched by synthetic biomaterials alone. Moreover, these raw materials provide a head start in the regeneration of tissues by providing building blocks to be bioresorbed and incorporated into the tissue as opposed to being biodegraded into waste products and removed. This article reviews the strategies and applications of employing raw materials as components of tissue engineering constructs. Utilizing raw materials holds the potential to provide both a scaffold and a signal, perhaps even without the addition of exogenous growth factors or cytokines. Raw materials contain endogenous proteins that may also help to improve the translational success of tissue engineering solutions to progress from laboratory bench to clinical therapies. Traditionally...

The Potential of Encapsulating “Raw Materials” in 3D Osteochondral Gradient Scaffolds

Mohan, Neethu; Gupta, Vineet; Sridharan, BanuPriya; Sutherland, Amanda; Detamore, Michael S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
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Scaffolds with continuous gradients in material composition and bioactive signals enable a smooth transition of properties at the interface. Components like chondroitin sulfate (CS) and bioactive glass (BG) in 3D scaffolds may serve as “raw materials” for synthesis of new extracellular matrix (ECM), and may have the potential to completely or partially replace expensive growth factors. We hypothesized that scaffolds with gradients of ECM components would enable superior performance of engineered constructs. Raw material encapsulation altered the appearance, structure, porosity, and degradation of the scaffolds. They allowed the scaffolds to better retain their 3D structure during culture and provided a buffering effect to the cells in culture. Following seeding of rat mesenchymal stem cells, there were several instances where glycosaminoglycan (GAG), collagen, or calcium contents were higher with the scaffolds containing raw materials (CS or BG) than with those containing transforming growth factor (TGF)-β3 or bone morphogenetic protein (BMP)-2. It was also noteworthy that a combination of both CS and TGF-β3 increased the secretion of collagen type II. Moreover, cells seeded in scaffolds containing opposing gradients of CS/TGF-β3 and BG/BMP-2 produced clear regional variations in the secretion of tissue-specific ECM. The study demonstrated raw materials have the potential to create a favorable microenvironment for cells; they can significantly enhance the synthesis of certain extracellular matrix (ECM) components when compared to expensive growth factors; either alone or in combination with growth factors they can enhance the secretion of tissue specific matrix proteins. Raw materials are promising candidates that can be used to either replace or be used in combination with growth factors. Success with raw materials in lieu of growth factors could have profound implications in terms of lower cost and faster regulatory approval for more rapid translation of regenerative medicine products to the clinic.

Estudo de Matérias-Primas do Rio Grande do Norte para Uso em Revestimento Poroso: Influência do teor de dolomita e temperatura de calcinação nas propriedades físico-mecânicas; Study of Raw materials of the Rio Grande do Norte for the use in Porous Wall Tile: Influence of the dolomite content and calcinations temperature in the physical- mechanical properties

Silva Neto, Gilson da
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ciência e Engenharia de Materiais; Processamento de Materiais a partir do Pó; Polímeros e Compósitos; Processamento de Materiais a part Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ciência e Engenharia de Materiais; Processamento de Materiais a partir do Pó; Polímeros e Compósitos; Processamento de Materiais a part
Tipo: Tese de Doutorado Formato: application/pdf
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The state of Rio Grande do Norte presents a great potentiality for the production of ceramic tiles because of having natural raw material in quantity and quality making its economical exploration possible, beyond the great energetic differential of the state, the natural gás. This works aims to study the influence of the dolomite and granulometry concentration and calcinations temperature in the obtaining of formulations for porous coverings which have to be coherent to the project,s specifications. The experiments have involved the physical-chemical and mineralogical characterizations of raw materials and mechanical tests in the dry and burnt proof bodies preceding a mixture experiment planning with the use of the response surface methodology, in order to get the best raw materials combinations to produce a ceramic mass with specific properties. The twelve ceramic masses studied in this work were prepared by the via dry process, characterized, shaped by uniaxial pressing and sinterized in the temperatures of 940ºC, 1000ºC, 1060ºC, 1120ºC and 1180ºC, using a fast burning cycle. The crystalline phases formed during the sintering in the temperatures in study have revealed the presence of anorthite and diopside beyond quartz with a remaining phase. These phases were the main responsible ones by the physical- mechanical properties of the sinterized proof bodies. The proof bodies after the sintering stage have presented water absorption higher than 10% and a good dimensional stability in all studied temperatures. However...

Produção de grês porcelanato a partir de matérias-primas do Rio Grande do Norte e queima a gás natural; Production of porcelainized stoneware tiles from raw materials of the State of Rio Grande do Norte and burns the natural gas

Pinheiro, Andréa Santos
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Mecânica; Tecnologia de Materiais; Projetos Mecânicos; Termociências Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Mecânica; Tecnologia de Materiais; Projetos Mecânicos; Termociências
Tipo: Dissertação Formato: application/pdf
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The State of Rio Grande do Norte, Brazil, possess major deposits of feldspar, clay, kaolin and talc, all raw materials used in the production of porcelainized stoneware tiles. Conversely, state industries manufacture only low added value red ceramics. Porcelainized stoneware tiles is one of the noblest ceramics, depicting low water absorption (typically below of 0,5%), in addition to excellent staining resistance and mechanical strength. The present work aims at investigating the potential of local raw materials for the production of porcelainized stoneware tiles. To that end, these materials were characterized by X-ray fluorescence, X-ray diffraction, particle size analysis, thermal gravimetric analysis and thermal differential analysis. Admixtures containing different compositions were prepared and fired at three temperatures, 1150, 1200 and 1250°C for 30 min. After firing, tests samples were characterized by water absorption tests, linear retraction, dilatometric analysis, apparent porosity, apparent specific mass, flexural strength, and microstructural analysis by XRD and SEM. The results revealed that ceramics with porcelainized stoneware tiles characteristics could be produced from raw materials originated in the State of Rio Grande do Norte; O Rio Grande do Norte possui grandes jazidas de pegmatitos...

Formulação e caracterização de massas de grês porcelanato preparadas a partir de matérias-primas naturais do Rio Grande do norte e com adição de chamote de telhas; Formulation and characterization of porcelanized stoneware tiles mixtures from regional raw materials and roofing tile chamote

Melo, Maxymme Mendes de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Mecânica; Tecnologia de Materiais; Projetos Mecânicos; Termociências Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Mecânica; Tecnologia de Materiais; Projetos Mecânicos; Termociências
Tipo: Dissertação Formato: application/pdf
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Traditional ceramics have an important role in the economy of Rio Grande do Norte. The local industries manufacture over 50 million shingles a month, corresponding to 60% of their overall production. As a result of processing flaws, roughly 20% of the production must be discarded, since little or no use has been envisaged for such fired components. Therefore, the use of this kind of residue, especially in the composition of other ceramic materials, comes as an interesting option from the economical and environmental point of view. In this scenario, the objective of the present study was to assess the effect of the addition of fired shingle waste in the composition of porcelainized stoneware tiles. To that end, two porcelainized stoneware tiles compositions were initially prepared. Subsequently, contents from 10 to 30% of roofing tiles chamote were added to each one of them. All raw materials and grog were characterized by FRX, XRD, and thermal analysis. The ceramics were fired using natural gas for 30 min at different temperatures, i.e. 1150, 1200 and 1250ºC, and fully characterized. The addition of roofing tiles chamote resulted in composition with superior properties compared to additive-free compositions. Porcelainized stoneware tiles products that fulfill required standards for practical applications were achieved; A indústria de cerâmica vermelha é um dos segmentos de maior importância na economia do Rio Grande do Norte. Nesse setor...

Cement Raw Materials in Indiana

McGregor, Duncan J.
Fonte: Indiana Geological Survey Publicador: Indiana Geological Survey
Tipo: Livro Formato: 35906544 bytes; application/pdf
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Indiana Geological Survey Bulletin 15; Limestone that is chemically suitable and easily accessible for cement manufacture can be found at many places in Indiana in the Mississippian limestones and to a more limited extent in the Devonian limestones. Clay, shale, and gypsum, also used in manufacturing cement, are readily available close to limestone reserves. Five areas in Indiana are most favorable for establishing cement plants: Bloomington-Spencer-Gosport, Paoli-Mitchell-Bedford, Greencastle, central Clark County, and southern Harrison County; a sixth area, east of Logansport, also may have limestone suitable for cement manufacture. Five of these areas are close to railroad lines and fuel supplies; the southern Harrison County area is favorably situated for barge transportation on the Ohio River. Reserves of mineral raw materials in 5 of the areas probably are sufficient to supply a cement plant for 50 years. Surface study does not permit an accurate appraisal of the Logansport area, but it probably also has sufficient reserves.; Indiana Department of Conservation

Towards an overall analytical framework for the integrated Sustainability Assessment of the Production and Supply of Raw Materials and Primary Energy Carriers

DEWULF JO; MANCINI LUCIA; BLENGINI GIOVANNI; SALA SERENELLA; LATUNUSSA CYNTHIA; PENNINGTON David
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Articles in periodicals and books Formato: Printed
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The sustainable production and supply of raw materials (‘non-energy raw materials’) and primary energy carriers (‘energy raw materials’) is at stake in many policies: their natural resource base for their production and supply, and the access to are limited; moreover, it is high on environmental and social impact agendas as well. A broad-in scope and quantitative framework that supports decision makers is recommended to make use of raw materials and primary energy carriers more sustainably. First, this paper proposes a holistic classification of the full set of raw materials and primary energy carriers our society relies on; this is an essential prerequisite when one aims at developing an Integrated Sustainability Assessment Framework (ISAF) that is to be applicable generically. Indeed, frequently only a subset of the raw materials and primary energy carriers is considered in function of the source, sector or final application. Here, overall 85 raw materials and 30 primary energy carriers are identified, grouped respectively into seven and five subgroups. Next, it proposes a quantitative ISAF of the production and supply of raw materials and primary energy carriers, envisaging all the sustainability pillars. Seeking for comprehensiveness...

Metamorphose des Steins – Vom Rohmaterial zum Kulturgut; Metamorhosis of stone-from raw material to cultural assets

Kieselbach, Petra
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
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In der vorliegenden Arbeit wurde das Silexmaterial von 14 jungneolithischen Siedlungen nach technologischen und typologischen Gesichtspunkten untersucht. Ziel war, das Produktionssystem für die verschiedenen Silexinventare, die sich anhand der Keramik den entsprechenden jungneo¬lithischen Kulturgruppen zuordnen lassen, herauszuarbeiten, um so die Differenzen bzw. Über¬einstimmungen für die verschiedenen jungneolithischen Kulturgruppen in räumlicher und zeit¬licher Hinsicht zu erfassen. Die Silexartefakte wurden hierzu im Rahmen einer Merkmalanalyse untersucht. Die Rohmaterialanalyse ergab für die verschiedenen Siedlungen eine unterschiedliche Nutzung von lokalen, regionalen und überregionalen Lagerstätten, die vor allem von der geographischen Lage der Siedlungen zu den Romateriallagerstätten bestimmt war. Danach versorgten sich die Siedlungen, die in der Nähe von gut verfügbaren Lagerstätten lokalisiert waren, vorwiegend mit lokalem Rohmaterial. Siedlungen mit weniger guten lokalen Rohmaterialquellen verwendeten hingegen verstärkt regionale und überregionale Rohmaterialien. In fast allen Silexinventaren bildete der von der Schwäbischen Alb stammende Jurahornstein das am häufigsten verwendete Rohmaterial. Eine Ausnahme stellen die Silexinventare der Michelsberger Kultur dar...

Incorporação do lodo de tanque séptico como matéria-prima de uma mistura asfáltica; Septic tank sludge applied as raw material of asphalt mixture

Medeiros, Sayonara Andrade de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-graduação em Engenharia Sanitária; Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-graduação em Engenharia Sanitária; Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica
Tipo: Dissertação Formato: application/pdf
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In Natal/RN, 68% of the population uses some kind of individual system for their domestic sewers treatment, being that the most used it is septic tank, followed by sumidouro. Every treatment system of sewers, usually used, generates a by-product denominated sludge. That residue presents some components, in its constitution, undesirable under the environmental and sanitary point of view. In such case, to assure that the system treatment has satisfactory results, it is necessary to do the adjusted disposition of the sludge sewage. Several countries are looking for technical alternatives for the use and disposition of residues. Under technical and environmental conditions appropriate, these materials can be used, decreasing the consumption of the natural resources and the treatment need, storage or elimination of the wastes, what decrease the risks created. Some of the alternatives of recycling of the sludge sewage are: the application in the agriculture, in the production of energy and as raw material in the civil construction. This study evaluated asphalt mixtures behavior that partially substituted conventional aggregates by septic tank sludge. The septic tank sludge gave origin to two raw materials called raw sludge and sludge ash. The raw sludge was put as a small aggregate and the sludge ash as filler. In the first experiment it was made a comparison between the mixture with conventional aggregates and the mixtures that replaced sand by raw sludge in the proportions from 5% to 40%. In the second experiment...

Caracterización mineralógica de materias primas cerámicas por métodos cuantitativos de difracción de rayos x; Mineralogical characterization of ceramic raw materials by powder quantitative X-ray diffraction methods

Rius, Jordi; Reventós, M. M.; Clausell, J. V.; Esteve, V.; Delgado, J. M.; Ochando, L. E.; Martí, F. J.; Amigó, J. M.
Fonte: Sociedad Española de Cerámica y Vidrio Publicador: Sociedad Española de Cerámica y Vidrio
Tipo: Artículo Formato: 681403 bytes; application/pdf
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[ES] El objetivo de este trabajo es la caracterización de fases minerales presentes en materias primas utilizadas en la industria cerámica. Para ello se utilizan dos métodos cuantitativos basados en la difracción de rayos X, el método de Rietveld y un método sin estándar. Los resultados obtenidos por difracción rayos X de estos materiales policristalinos se comparan con los correspondientes análisis químicos y la composición normativa calculada. La precisión y reproducibilidad de los resultados obtenidos, en concordancia con los del análisis químico, son una de las más importantes ventajas de la difractometría cuantitativa que facilitan su utilización en la industria cerámica en el control de las fases minerales presentes en las materias primas.; [EN] The aim of this work is to characterize mineral phases present in raw material employed in the ceramics industry. In this way, two quantitative X-ray diffraction methods have been used, the Rietveld and the standardless methods have been used. The results obtained by X-ray diffraction of these polycrystalline materials are compared with the corresponding chemical analyses and calculated normative composition. Precision and reproducibility of obtained results...

Características generales, propiedades, yacimientos y aplicaciones de pirofilita. II. Yacimientos, aplicaciones y utilización como materia prima cerámica; Pyrophyllita. General Properties. Part II: Deposits, applications and uses as ceramic raw material

Sánchez-Soto, Pedro José; Pérez Rodríguez, José Luis
Fonte: Sociedad Española de Cerámica y Vidrio Publicador: Sociedad Española de Cerámica y Vidrio
Tipo: Artículo Formato: 425705 bytes; application/pdf
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[ES] En este trabajo se indican los principales yacimientos mundiales de pirofilita según la bibliografía, los datos de producción disponibles, además de revisar las investigaciones más destacadas sobre prospección y caracterización de materias primas que contenienen pirofilita y que presentan un marcado interés aplicado. Se realiza una amplia revisión de las principales aplicaciones a las que se destinan dichas materias primas, en especial para la preparación de materiales cerámicos y refractarios, su uso como carga, en la construcción, obtención de catalizadores y síntesis de materiales a alta presión debido a sus propiedades. Por último, se describen y revisan sus aplicaciones en la preparación de nuevos materiales y materiales avanzados, como son los sialones, destacando su potencial de utilización en nuestro país como resultado de diversas investigaciones de interés, realizadas por distintos Institutos y Departamentos universitarios. Se deduce que la pirofilita adquiere una importancia relativa cada vez mayor en relación a otros silicatos laminares, como son talco y caolinita.; [EN] In this work, the main world deposits of pyrophyllite are indicated according to the literature, showing the available production data. It is emphasized the research focusing on mining and characterization of raw materials containing pyrophyllite...

Aplicación de Sistemas de Información Geográfica (SIG) en la prospección y caracterización de materias primas de interés en Cerámica y Vidrio; Application of Geographic Infomration Systems (GIS) in the search for and characterization of raw materials of interest in ceramics and glass

Ruíz-Conde, Antonio; Sánchez-Soto, Pedro José; Garzón Garzón, Eduardo; García, I. G.
Fonte: Sociedad Española de Cerámica y Vidrio Publicador: Sociedad Española de Cerámica y Vidrio
Tipo: Artículo Formato: 1096333 bytes; application/pdf
Português
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[ES] En este trabajo se muestra la aplicación de un sistema de información geográfica (SIG) como herramienta eficaz a la hora de abordar varias fases de investigación sobre materias primas de interés para el sector de la Cerámica y el Vidrio, con dos ejemplos: prospección y caracterización de materias primas, utilizadas como material impermeabilizante además de potencial interés cerámico y estudio de canteras de extracción de caliza y mármol. Para ello, se han diferenciado tres fases en el trabajo: construcción de la base de datos cartográfica, fusión de las bases de datos y depuración; finalmente, se realiza el desarrollo de la aplicación. De este estudio se concluye que el SIG se convierte en una herramienta viva, a la que se le pueden ir incorporando nuevos datos, como son puntos de muestreo, resultados de ensayos y determinaciones realizadas con las muestras, nuevas vías y caminos, empresas que poseen la concesión, etc., como ha quedado expuesto con los ejemplos descritos. Todo ello permite una explotación mucho más racional y eficiente desde los puntos de vista técnico, medioambiental y económico. Se deduce un claro interés del método de trabajo propuesto con utilidad para investigadores, tecnólogos y empresarios del ámbito que se ocupan de la valorización de materias primas de aplicación en el procesamiento de materiales de este sector.; [EN] This work shows the application of a geographic information system (GIS) as an effective tool to undertake several phases of research on raw materials of interest in ceramics and glass...

Trade in raw materials and economic development

Garred, Jason
Fonte: London School of Economics and Political Science Thesis Publicador: London School of Economics and Political Science Thesis
Tipo: Thesis; NonPeerReviewed Formato: text
Publicado em /05/2015 Português
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47.917324%
This thesis considers three cases in which trade in natural resources and other raw materials can inform us about wider questions of economic development. The first chapter, “Capturing the Value Chain: The Persistence of Trade Policy in China After WTO Accession”, considers whether in the GATT/WTO era, developing countries are still able to actively conduct trade policy. In this study, I show that after China’s entry into WTO, required import tariff reductions on downstream sectors have been partly offset by an alternative policy with similar effects: export restrictions on raw materials. I also find that larger rises in Chinese raw materials export taxes after WTO accession have been associated with greater downstream export growth. The second chapter, “Winners and Losers from a Commodities-for-Manufactures Trade Boom”, examines two contrasting outcomes of the ‘de-industrialization’ associated with rising trade between China and other developing countries. In particular, this chapter compares changes in labour market outcomes in Brazilian regions stimulated by rising demand from China for raw materials, with Brazilian regions whose manufacturing sectors have been harmed by Chinese import competition. While there was slower growth in manufacturing wages and greater rises in local wage inequality in ‘loser’ regions between 2000 and 2010...

A practical application of geostatistical methods to quality and mineral reserve modelling of cement raw materials

Yunsel,T.Y.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2012 Português
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67.616973%
Estimation techniques such as polygonal, triangular prism, trapezoid, isopach maps, and inverse distance methods are often used in ore or industrial minerals deposit evaluation. These techniques do not express the variability of the deposit and do not allow a determination of the reliability of the estimates. However, geostatistical methods can express a measure of the error associated with the estimates, by finding weighting coefficients for a given mining block, and can also help with data configuration that minimizes the error. This work addresses an application study on the quality and reserve characteristics of the cement raw materials of the Adana Cement Factory in Adana, Turkey, based on the spatial distribution and variability of the chemical components (SiO2, CaO, Al2O3, Fe2O3). The study has been carried out using a geostatistical procedure that is useful for site assessment, characterization, and monitoring situations where data are collected spatially. Directional and omnidirectional experimental variograms of the cement raw material variables showed that neither strong geometric nor severe zonal anisotropy exists in the data. The most evident spatial dependence structure expressing the continuity for omnidirectional experimental variograms were characterized by exponential and spherical variogram models. These models have been used in cross-validation analysis...